TS-239 Pro II - use RAID-0 or JBOD? EXT3 or EXT4?

[occamsrazor]

So I bit the bullet and ordered a QNAP TS-239 Pro II, which am going to use with 2 x 2TB WD20EADS drives. I've read there's some problems with some Green drives, although QNAP say this particular model is OK, but will try anyway.

The drives will be storing mainly movies, music, and Time Machine backups, and I need to get the full capacity from the drives. I plan to manually backup the essential files to an external eSATA drive. Therefore I'm thinking to format the unit as Raid-0 or JBOD, not RAID-1.

Should I go for Raid-0 or JBOD? Will RAID-0 provide significantly greater speed compared to JBOD? I don't see JBOD mentioned in the charts...

Will RAID-0 be significantly louder, hotter and/or use more power?

Also, should I format as EXT3 or EXT4? I read there were some problems with the current implementation of EXT4 that were going to be fixed in a new firmware update, what are the pros and cons?

Most of my machines are Macs....

Thanks for your help. Also if anyone has experience with Jumbo Frames and Link Aggregation on this unit, please see this thread in the Switches forum.

 

[thiggins]

If a NAS Chart benchmark doesn't specify a RAID level, multi-drive NASes are tested in RAID 0.

If you look at the difference between the default (1000 Mbps Average Write / Read Performance) and RAID 1 tests you generally don't see much difference. I don't test JBOD, but I would not expect significant difference there either.

Using either JBOD or RAID 0 if you lose either disk, you lose all your data.
Consider using individual volumes for each drive. That way if you lose one drive, you lose only the data on that drive. Downside is that you may end up with a bit of unused space on each drive.

There is no difference in power consumption, noise, heat in either mode.

EXT3 should be fine. EXT4 is primarily needed for larger volume sizes. The ext4 filesystem can support volumes with sizes up to 1 exabyte and files with sizes up to 16 terabytes. See http://en.wikipedia.org/wiki/Ext4

 

[joeybaker]

I hear that loosing half your capacity to RAID 1 is painful, but let me just voice some opposition to your plan.

You've just shelled out a lot of money to have a painless, easy-to-use, backup solution that you expect to operate without and problems. The very last thing you want to do is use a RAID 0 configuration.

There's a saying that someone told me when I experienced my first hard drive failure –*"Everyone has a harddrive fail on them – once. Then they learn." I've had harddrives die on me since – but I'll never again loose a drive with irreplaceable data.

What your proposing sets you up to loose all your data – without any hope of recovery. RAID 0 is used to increase system performance. It stripes the data – which means each drive gets half of every piece of data. If one drive goes, they both go. Great for speed, horrible for reliability.

If you really can't afford to shell out the money now, I'd recommend that you play it risky –*RAID 0 your drives, and as soon as you can, double your capacity so you can have RAID 1 + 0 – that will give you the performance perks with the backup capabilities.

Alternatively, you could just increase your storage capacity by 50% (buy another 2 TB drive) and use RAID 5 – you'll only get 2/3 of your storage capacity, but you'll get that nice redundancy.

In summary – DANGER WILL ROBINSON!

 

[thiggins]

Running in any mode, RAID 0, 1, 5, 6, 10, JBOD or individual drive is fine.

Just make sure your critical data (anything you don't want to lose) is backed up on at least one other device.

 

[occamsrazor]

You've just shelled out a lot of money to have a painless, easy-to-use, backup solution that you expect to operate without and problems. The very last thing you want to do is use a RAID 0 configuration.

As regards using the NAS as a backup for my 3 computers, using RAID-0 doesn't worry me *that* much. The only time I'd need it seriously was if my computers hard drive got screwed up, and I figure the chance of that happening AND the NAS dying at the same time is minimal. If the NAS drives die but not the computers I still haven't lost data. The only scenario I could see that happening is with a power surge and I have pretty good UPS and surge protectors.

There's a saying that someone told me when I experienced my first hard drive failure –*"Everyone has a harddrive fail on them – once. Then they learn."

I agree with that. I've had a number of drives die on me, and fortunately had backups.

What your proposing sets you up to loose all your data – without any hope of recovery.

It would if I was planning to keep the data solely on the NAS, yes, but regards the Time Machine backups the original data is also on the computers, so that doesn't worry me.

If you really can't afford to shell out the money now, I'd recommend that you play it risky –*RAID 0 your drives, and as soon as you can, double your capacity so you can have RAID 1 + 0 – that will give you the performance perks with the backup capabilities.

I will probably do something fairly similar - Have the NAS formatted as individual volumes or JBOD or Raid-0, then when I can afford some more drives back it up to an eSATA device. Tim indicated the transfer speed on this model wasn't greatly different between the different formats, so I'll probably go with individual volumes as it seems to carry less risk.

Alternatively, you could just increase your storage capacity by 50% (buy another 2 TB drive) and use RAID 5 – you'll only get 2/3 of your storage capacity, but you'll get that nice redundancy.

It's a 2-drive NAS, I can't do Raid-5. I considered a 4-drive NAS but decided against based on noise levels. Raid-5 would have given me redundancy, but in my experience "human error" is the greatest risk, and I would rather have an actual backup.

In summary – DANGER WILL ROBINSON!

You're quite right to point out the risks, although I disagree that using a Raid-0 device as a backup of a computer is necessarily a very bad idea.

All that said I will also be storing a lot (1.3TB) of movies on the NAS, so I will probably try to do a backup of that (but not the Time Machine files) to a separate drive.

I appreciate your advice and comments, thanks....

 

[ChrisInOz]

occamsrazor, I'd be interested to hear your your experiences with the TS-239 Pro II, in particular the eSATA backup. I am thinking of buying one myself.

Thanks,
Chris

 

[occamsrazor]

Sorry Chris, I haven't had the chance to try the eSATA backup yet...

 

[thiggins]

occamsrazor, I'd be interested to hear your your experiences with the TS-239 Pro II, in particular the eSATA backup. I am thinking of buying one myself.

Check the NAS Charts, Backup benchmarks. I had forgotten to add the backup results.

Basically, it tops the charts with 80+ MB/s using FAT, EXT3 or even NTFS formatted eSATA drives.

 

[ChrisInOz]

Thanks for that Tim, it seems to perform very well. I am actually more interested in the stability of the backups. I read the thread on issues with backups on QNAPs and it seemed like people were having quite a few issues backing up to USB and eSATA devices.

Chris

 

[thiggins]

I have two rsync backup jobs that run daily from a TS-109 to a Synology DS109+ with no problems. Can't speak to any issues with USB or eSATA backups other than the few jobs I've run when testing the products execute with no problems.